/*
 * This is an OpenSSL-compatible implementation of the RSA Data Security, Inc.
 * MD5 Message-Digest Algorithm (RFC 1321).
 *
 * Homepage:
 * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
 *
 * Author:
 * Alexander Peslyak, better known as Solar Designer <solar at openwall.com>
 *
 * This software was written by Alexander Peslyak in 2001.  No copyright is
 * claimed, and the software is hereby placed in the public domain.
 * In case this attempt to disclaim copyright and place the software in the
 * public domain is deemed null and void, then the software is
 * Copyright (c) 2001 Alexander Peslyak and it is hereby released to the
 * general public under the following terms:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted.
 *
 * There's ABSOLUTELY NO WARRANTY, express or implied.
 *
 * (This is a heavily cut-down "BSD license".)
 *
 * This differs from Colin Plumb's older public domain implementation in that
 * no exactly 32-bit integer data type is required (any 32-bit or wider
 * unsigned integer data type will do), there's no compile-time endianness
 * configuration, and the function prototypes match OpenSSL's.  No code from
 * Colin Plumb's implementation has been reused; this comment merely compares
 * the properties of the two independent implementations.
 *
 * The primary goals of this implementation are portability and ease of use.
 * It is meant to be fast, but not as fast as possible.  Some known
 * optimizations are not included to reduce source code size and avoid
 * compile-time configuration.
 */

#ifndef HAVE_OPENSSL

#include <string.h>
#if defined(_MSC_VER)
#pragma warning(disable:4244)
#endif
#include "md5.h"

/*
 * The basic MD5 functions.
 *
 * F and G are optimized compared to their RFC 1321 definitions for
 * architectures that lack an AND-NOT instruction, just like in Colin Plumb's
 * implementation.
 */
#define F(x, y, z)			((z) ^ ((x) & ((y) ^ (z))))
#define G(x, y, z)			((y) ^ ((z) & ((x) ^ (y))))
#define H(x, y, z)			((x) ^ (y) ^ (z))
#define I(x, y, z)			((y) ^ ((x) | ~(z)))

/*
 * The MD5 transformation for all four rounds.
 */
#define STEP(f, a, b, c, d, x, t, s) \
	(a) += f((b), (c), (d)) + (x) + (t); \
	(a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s)))); \
	(a) += (b);

/*
 * SET reads 4 input bytes in little-endian byte order and stores them
 * in a properly aligned word in host byte order.
 *
 * The check for little-endian architectures that tolerate unaligned
 * memory accesses is just an optimization.  Nothing will break if it
 * doesn't work.
 */
#if defined(__i386__) || defined(__x86_64__) || defined(__vax__)
#define SET(n) \
	(*(MD5_u32plus *)&ptr[(n) * 4])
#define GET(n) \
	SET(n)
#else
#define SET(n) \
	(ctx->block[(n)] = \
	(MD5_u32plus)ptr[(n) * 4] | \
	((MD5_u32plus)ptr[(n) * 4 + 1] << 8) | \
	((MD5_u32plus)ptr[(n) * 4 + 2] << 16) | \
	((MD5_u32plus)ptr[(n) * 4 + 3] << 24))
#define GET(n) \
	(ctx->block[(n)])
#endif

/*
 * This processes one or more 64-byte data blocks, but does NOT update
 * the bit counters.  There are no alignment requirements.
 */
static void *body ( MD5_CTX *ctx, void *data, unsigned long size )
{
   unsigned char *ptr;
   MD5_u32plus a, b, c, d;
   MD5_u32plus saved_a, saved_b, saved_c, saved_d;

   ptr = data;

   a = ctx->a;
   b = ctx->b;
   c = ctx->c;
   d = ctx->d;

   do {
      saved_a = a;
      saved_b = b;
      saved_c = c;
      saved_d = d;

      /* Round 1 */
      STEP ( F, a, b, c, d, SET ( 0 ), 0xd76aa478, 7 )
         STEP ( F, d, a, b, c, SET ( 1 ), 0xe8c7b756, 12 )
         STEP ( F, c, d, a, b, SET ( 2 ), 0x242070db, 17 )
         STEP ( F, b, c, d, a, SET ( 3 ), 0xc1bdceee, 22 )
         STEP ( F, a, b, c, d, SET ( 4 ), 0xf57c0faf, 7 )
         STEP ( F, d, a, b, c, SET ( 5 ), 0x4787c62a, 12 )
         STEP ( F, c, d, a, b, SET ( 6 ), 0xa8304613, 17 )
         STEP ( F, b, c, d, a, SET ( 7 ), 0xfd469501, 22 )
         STEP ( F, a, b, c, d, SET ( 8 ), 0x698098d8, 7 )
         STEP ( F, d, a, b, c, SET ( 9 ), 0x8b44f7af, 12 )
         STEP ( F, c, d, a, b, SET ( 10 ), 0xffff5bb1, 17 )
         STEP ( F, b, c, d, a, SET ( 11 ), 0x895cd7be, 22 )
         STEP ( F, a, b, c, d, SET ( 12 ), 0x6b901122, 7 )
         STEP ( F, d, a, b, c, SET ( 13 ), 0xfd987193, 12 )
         STEP ( F, c, d, a, b, SET ( 14 ), 0xa679438e, 17 )
         STEP ( F, b, c, d, a, SET ( 15 ), 0x49b40821, 22 )

         /* Round 2 */
         STEP ( G, a, b, c, d, GET ( 1 ), 0xf61e2562, 5 )
         STEP ( G, d, a, b, c, GET ( 6 ), 0xc040b340, 9 )
         STEP ( G, c, d, a, b, GET ( 11 ), 0x265e5a51, 14 )
         STEP ( G, b, c, d, a, GET ( 0 ), 0xe9b6c7aa, 20 )
         STEP ( G, a, b, c, d, GET ( 5 ), 0xd62f105d, 5 )
         STEP ( G, d, a, b, c, GET ( 10 ), 0x02441453, 9 )
         STEP ( G, c, d, a, b, GET ( 15 ), 0xd8a1e681, 14 )
         STEP ( G, b, c, d, a, GET ( 4 ), 0xe7d3fbc8, 20 )
         STEP ( G, a, b, c, d, GET ( 9 ), 0x21e1cde6, 5 )
         STEP ( G, d, a, b, c, GET ( 14 ), 0xc33707d6, 9 )
         STEP ( G, c, d, a, b, GET ( 3 ), 0xf4d50d87, 14 )
         STEP ( G, b, c, d, a, GET ( 8 ), 0x455a14ed, 20 )
         STEP ( G, a, b, c, d, GET ( 13 ), 0xa9e3e905, 5 )
         STEP ( G, d, a, b, c, GET ( 2 ), 0xfcefa3f8, 9 )
         STEP ( G, c, d, a, b, GET ( 7 ), 0x676f02d9, 14 )
         STEP ( G, b, c, d, a, GET ( 12 ), 0x8d2a4c8a, 20 )

         /* Round 3 */
         STEP ( H, a, b, c, d, GET ( 5 ), 0xfffa3942, 4 )
         STEP ( H, d, a, b, c, GET ( 8 ), 0x8771f681, 11 )
         STEP ( H, c, d, a, b, GET ( 11 ), 0x6d9d6122, 16 )
         STEP ( H, b, c, d, a, GET ( 14 ), 0xfde5380c, 23 )
         STEP ( H, a, b, c, d, GET ( 1 ), 0xa4beea44, 4 )
         STEP ( H, d, a, b, c, GET ( 4 ), 0x4bdecfa9, 11 )
         STEP ( H, c, d, a, b, GET ( 7 ), 0xf6bb4b60, 16 )
         STEP ( H, b, c, d, a, GET ( 10 ), 0xbebfbc70, 23 )
         STEP ( H, a, b, c, d, GET ( 13 ), 0x289b7ec6, 4 )
         STEP ( H, d, a, b, c, GET ( 0 ), 0xeaa127fa, 11 )
         STEP ( H, c, d, a, b, GET ( 3 ), 0xd4ef3085, 16 )
         STEP ( H, b, c, d, a, GET ( 6 ), 0x04881d05, 23 )
         STEP ( H, a, b, c, d, GET ( 9 ), 0xd9d4d039, 4 )
         STEP ( H, d, a, b, c, GET ( 12 ), 0xe6db99e5, 11 )
         STEP ( H, c, d, a, b, GET ( 15 ), 0x1fa27cf8, 16 )
         STEP ( H, b, c, d, a, GET ( 2 ), 0xc4ac5665, 23 )

         /* Round 4 */
         STEP ( I, a, b, c, d, GET ( 0 ), 0xf4292244, 6 )
         STEP ( I, d, a, b, c, GET ( 7 ), 0x432aff97, 10 )
         STEP ( I, c, d, a, b, GET ( 14 ), 0xab9423a7, 15 )
         STEP ( I, b, c, d, a, GET ( 5 ), 0xfc93a039, 21 )
         STEP ( I, a, b, c, d, GET ( 12 ), 0x655b59c3, 6 )
         STEP ( I, d, a, b, c, GET ( 3 ), 0x8f0ccc92, 10 )
         STEP ( I, c, d, a, b, GET ( 10 ), 0xffeff47d, 15 )
         STEP ( I, b, c, d, a, GET ( 1 ), 0x85845dd1, 21 )
         STEP ( I, a, b, c, d, GET ( 8 ), 0x6fa87e4f, 6 )
         STEP ( I, d, a, b, c, GET ( 15 ), 0xfe2ce6e0, 10 )
         STEP ( I, c, d, a, b, GET ( 6 ), 0xa3014314, 15 )
         STEP ( I, b, c, d, a, GET ( 13 ), 0x4e0811a1, 21 )
         STEP ( I, a, b, c, d, GET ( 4 ), 0xf7537e82, 6 )
         STEP ( I, d, a, b, c, GET ( 11 ), 0xbd3af235, 10 )
         STEP ( I, c, d, a, b, GET ( 2 ), 0x2ad7d2bb, 15 )
         STEP ( I, b, c, d, a, GET ( 9 ), 0xeb86d391, 21 )

         a += saved_a;
      b += saved_b;
      c += saved_c;
      d += saved_d;

      ptr += 64;
   } while ( size -= 64 );

   ctx->a = a;
   ctx->b = b;
   ctx->c = c;
   ctx->d = d;

   return ptr;
}

void MD5_Init ( MD5_CTX *ctx )
{
   ctx->a = 0x67452301;
   ctx->b = 0xefcdab89;
   ctx->c = 0x98badcfe;
   ctx->d = 0x10325476;

   ctx->lo = 0;
   ctx->hi = 0;
}

void MD5_Update ( MD5_CTX *ctx, void *data, unsigned long size )
{
   MD5_u32plus saved_lo;
   unsigned long used, free;

   saved_lo = ctx->lo;
   if ( (ctx->lo = (saved_lo + size) & 0x1fffffff) < saved_lo )
      ctx->hi++;
   ctx->hi += size >> 29;

   used = saved_lo & 0x3f;

   if ( used ) {
      free = 64 - used;

      if ( size < free ) {
         memcpy ( &ctx->buffer[used], data, size );
         return;
      }

      memcpy ( &ctx->buffer[used], data, free );
      data = (unsigned char *) data + free;
      size -= free;
      body ( ctx, ctx->buffer, 64 );
   }

   if ( size >= 64 ) {
      data = body ( ctx, data, size & ~(unsigned long) 0x3f );
      size &= 0x3f;
   }

   memcpy ( ctx->buffer, data, size );
}

void MD5_Final ( unsigned char *result, MD5_CTX *ctx )
{
   unsigned long used, free;

   used = ctx->lo & 0x3f;

   ctx->buffer[used++] = 0x80;

   free = 64 - used;

   if ( free < 8 ) {
      memset ( &ctx->buffer[used], 0, free );
      body ( ctx, ctx->buffer, 64 );
      used = 0;
      free = 64;
   }

   memset ( &ctx->buffer[used], 0, free - 8 );

   ctx->lo <<= 3;
   ctx->buffer[56] = ctx->lo;
   ctx->buffer[57] = ctx->lo >> 8;
   ctx->buffer[58] = ctx->lo >> 16;
   ctx->buffer[59] = ctx->lo >> 24;
   ctx->buffer[60] = ctx->hi;
   ctx->buffer[61] = ctx->hi >> 8;
   ctx->buffer[62] = ctx->hi >> 16;
   ctx->buffer[63] = ctx->hi >> 24;

   body ( ctx, ctx->buffer, 64 );

   result[0] = ctx->a;
   result[1] = ctx->a >> 8;
   result[2] = ctx->a >> 16;
   result[3] = ctx->a >> 24;
   result[4] = ctx->b;
   result[5] = ctx->b >> 8;
   result[6] = ctx->b >> 16;
   result[7] = ctx->b >> 24;
   result[8] = ctx->c;
   result[9] = ctx->c >> 8;
   result[10] = ctx->c >> 16;
   result[11] = ctx->c >> 24;
   result[12] = ctx->d;
   result[13] = ctx->d >> 8;
   result[14] = ctx->d >> 16;
   result[15] = ctx->d >> 24;

   memset ( ctx, 0, sizeof ( *ctx ) );
}

#endif
